This project will develop an artificial intelligence to provide the core functionality for virtual reality and computer based treatments for anxiety disorders. The use of artificial intelligence offers a number of advantages over existing treatments: (1) artificial intelligence provides personalized treatment - using multiple real time physiologic and subjective anxiety feedback loops, it adjusts exposure stimuli "on the fly" to maximize outcome, (2) as an autonomous system, it has the potential to be used safely in a wide range of applications from therapist guided interventions to minimal therapist contact interventions to self guided treatment, (3) it is adaptive and flexible, continuously learning what works and doesn't work, applying those changes in real time, and storing them for later use, (4) it can monitor levels of presence and adjust patient/exposure variables to ensure the depth of presence necessary to benefit from virtual reality treatments, and (5) it has the potential to increase retention in treatment by monitoring factors that predict drop out and adjusting exposure to minimize their effect. During Phase I eighty phobic and non-phobic participants will be used to build, assess, and validate the artificial intelligence. This is the first application of artificial intelligence to virtual reality treatments for anxiety disorders.